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Discussion Starter · #1 ·
Anyone ever take a bandsaw to one of these things? Or found a detailed cutaway drawing? Flow diagram?

I am trying to figure out exactly which cavities on the 'draw' side of the impeller have external surfaces I can tap a port into. It's going to be no fun taking a hacksaw to one, but I will do it if I have to.
 

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Discussion Starter · #4 ·
May I ask what for?
You may, but I am not going to tell you. It's a surprise, the likes this forum has never seen :p

Actually, I am just doing some underhood cleanup with the new 395. Since I have never liked that massive plastic expansion tank on the fender well, it's not going to survive the swap. What I am doing in it's place is mounting one of these:
http://www.summitracing.com/parts/CTR-80-202/


to the front of the driver's side head since that area is going to be vacant. The steam tube is going to be plumbed into the upper port on the side and the return on the bottom is going to be plumbed back into the water pump. This needs to be a cavity that the impeller is drawing from, not pumping into.

The stock system has the expansion tank plumbed into the heater hose return line, which dumps directly into the cavity that feeds the impeller...where the thermostat resides. That is my first choice, but it's on the opposite side of the pump from the tank. It seems to me that the lower portion of the pump (where the coolant temp sensor resides) is also low pressure, but fluid from there still needs to flow through the bottom of the thermostat to get to the impeller and wouldn't be at as low of pressure as the heater hose return.

There, now you know as much as I know...on this subject, at least. :D
 

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Try an F body water pump. I believe it has the port you need.

-Nab
 

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Now that is a reason I was never going to guess. That's an interesting choice of location too. Good luck.
 

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Discussion Starter · #7 ·
Try an F body water pump. I believe it has the port you need.
I looked at that first, but it's on the pressure side of the impeller:


The most convenient position would be the coolant temp sensor hole, but then I have to move the sensor. I can easily tap the blank boss above (where the F-car 'extra' hose goes), but it seems like a bad place for a temperature reading since some of the coolant would have just come from the radiator when the thermostat is open. I really don't want to stick it in the head between all of the header tubes and plug wires.

I'm going to try and probe around the underside some more and see if I can find a better place. It is a longshot to see if someone has one hacked up, but I have an intake that is all chopped up.
 

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Why not just tap into the runner next to the temp sensor?
 

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Well sir Knight,
If you want pictures of a hacked up one, it just so happens I have a junk one and access to a ban saw.
Is there a special direction you want it cut?
 

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Discussion Starter · #13 · (Edited)
Why not just tap into the runner next to the temp sensor?
I thought about that but there isn't a lot of room there (since I was planning to run at least -06). There is more room around the side, though. Pics below.



Why not just T the temp sensor.
That is a good idea, but would involve some kind of a bulky fitting there and it gets the sensor out of the stream of water coming from the engine. I know it's a small nit, but I really like having the sensors knowing as soon as possible when something changes. Seems that if it were relying on the temperature of the water coming out of the expansion tank back into the pump, there could easily be a big lag between when the engine heats up under load and when the sensor gets that hot coolant across the tip.

As I looked at the pump more and more, I decided that the only part that is guaranteed to have the lowest pressure in the system is the cavity that feeds the impeller. Where the thermostat resides. If I tap into the cavity where the ECT sensor resides, the pressure drop will be much less once the coolant heats up and the thermostat opens. Sometimes when you look at something long enough, a decent solution kind of presents itself. In this case, it's just tapping (wish I had a TiG welder) a -06AN fitting into the body directly behind the thermostat. Routing the hose won't be quite as convenient as I had hoped, but it won't be bad.

Of course, there will be pictures once I get the pump back from my buddy who owns the appropriate equipment do do the work :D
 

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Discussion Starter · #14 ·
Well sir Knight,
If you want pictures of a hacked up one, it just so happens I have a junk one and access to a ban saw.
Is there a special direction you want it cut?
Tempting, very tempting. I know what I need to know about the flow just from looking at it long enough and don't need to look inside any more. The only part I can't get a good feel for is where the coolant goes up in the pump body. I think it would be really interesting to see one of these cut vertically right through the temp sensor. Don't feel obligated to cut it on my account, but please be sure to post pictures if you do!
 

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This water pump was just setting there minding it's own business,
and a ban saw fell on it.....
Hope you enjoy it :).
 

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Discussion Starter · #17 ·
This water pump was just setting there minding it's own business,
and a ban saw fell on it.....
Hope you enjoy it :).
I do. That was very nice of that waterpump to commit suicide for us. Thank you very much.

When I get some time, I want to take an old pump and paint it up to show exactly where the coolant flows and why. It's not obvious cwm3
 

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Discussion Starter · #18 ·
Finally getting some time to work on the project lately. Got the plate fabbed up to hold the expansion tank:


Since both the head and tank overlap, the tank mounting holes are threaded and bolts used from the backside as studs:


Mounted to the head:


And then with the tank mounted:






As long as we were modifying the pump housing, I added two more 3/8" NPT bosses. The one behind the thermostat is where I am going to feed the returning coolant from the bottom of the tank. This is the lowest pressure cavity in the pump whether the thermostat is open or closed and should provide the same draw against the steam tube as the factory intended. The one on the underside with the temperature sensor is just for fun :D Well, that and it leaves the original one open at the front just in case I want to have a dedicated one to let the cooling system automatically run after I shut the engine off:


 

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Looking good Scott-- top notch work

I am going to have to fly out to ride in this beast-- :D
 

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Very innovative!

Keep us posted.
 
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